1. Field
This invention relates to wireless communication networks, and in particular, wireless networks in which devices transmit beacons.
2. Description of the Related Technology
A wireless communication network is commonly associated with a communication network where the interconnections among the devices of the network are implemented without the use of wires. Such networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier.
A wireless personal area network (WPAN) is one type of wireless network used for communication among a plurality of devices, such as computers, mobile phones, personal digital assistants, printers, digital cameras, televisions, media players, etc. Usually, a WPAN covers a short range up to 10 or 20 meters. A number of standards for such short-range network communications have recently been developed, including Bluetooth and IEEE 802.15, for example.
Millimeter wave (mmW) wireless communication in and around the 60 GHz frequency band has the potential to provide a large bandwidth capacity and has thus drawn research interest from both academia and industry. With mmW technology, uncompressed high-definition video/audio can be transmitted wirelessly with similar visual quality to that achieved when using video cables such as High Definition Multimedia Interface (HMDI) cables or Digital Video Interface (DVI) cables. In addition, mmW wireless technology can enable other applications, such as a video kiosk, a fast hard disk or other system back-up, or other applications requiring fast and reliable communication of large amounts of data.
At 60 GHz, there is greater free space loss of power than at 2 or 5 GHz, since such loss can be approximated by a function which quadratically increases with frequency. Nevertheless, this higher free space loss can be at least partially compensated for through the use of directional transmission. A simple directional transmission solution is to use a sectored antenna. By using such an antenna, the transmitter is physically directed towards the receiver. Other technologies, such as beamforming, can use multiple antennas to obtain greater pattern directivity while maintaining small antenna dimensions.
Although directional transmission can improve link quality, it may also introduce new challenges to network control and management, such as control and management of a wireless personal area network. A wireless personal area network (WPAN) system is a computer network used in communication between devices (for example, portable computers, telephones, or personal digital assistants) that are located close to an individual. The devices may or may not belong to that individual. The reach of a WPAN is typically a few meters, but may be more under certain circumstances. A WPAN may be used to communicate between the devices, or to interconnect with a higher level network such as the internet. A number of standards for network communications have recently been developed, including, but not limited to, Bluetooth and IEEE 802.15.